"India has reason to be disappointed that Sri Lanka has failed to uphold its commitments to New Delhi, to the international community and to the people of Sri Lanka," the rights body said in a statement.

"We hope that India will continue to encourage the Rajapaksa government to do the right thing to ensure reconciliation, devolution of power and justice," said Meenakshi Ganguly, its South Asia director.

Rajapaksa, who is set to visit India this week on a pilgrimage, has come out against devolving powers to provinces, a statement seen as a U-turn on the promises he has made to Indian leaders in the past.

Rights bodies have also criticised Sri Lanka for failing to investigate allegations that thousands of civilians were killed in the final months of war against the Tamil Tigers that ended in May 2009.